The present invention relates generally to a keyless entry system for operating automotive vehicle devices, such as door locks, a trunk lid lock, a glove box lid lock, a steering lock device, a starter motor, etc. without mechanical keys. More particularly, the invention relates to a keyless entry system which employ radio waves carrying a preset code.
Conventionally, automotive door locks, trunk lid locks, glove box locks, steering lock devices and so forth in automotive vehicles have been operated by means of ignition or other keys in the past. Recently however, so-called "Keyless Entry Systems", which do not require keys to operate a door locks, a trunk locks, vehicle windows and so forth, have been developed. In the keyless entry system, a keyboard is provided on the external surface of the vehicle body to allow entry of a predetermined code authorizing access to one or more desired vehicle devices. The designated vehicle devices are electrically operated when the entered code matches a predetermined code.
Although such keyless entry systems have been well developed and considered useful because they do not require mechanical keys, a serious problem may occur when the user of the vehicle forgets the predetermined code. If the user is outside of the vehicle and the vehicle door lock device is holding the door locked, the user cannot unlock the door locks until he remembers the predetermined code.
The present invention provides a novel and more useful system for operating the vehicle devices without an ignition key and without requiring manual entry of a predetermined code.